JPH02288575A - Electronic still camera equipment - Google Patents

Abstract

PURPOSE:To attain accurate white balance control even when a light of a strobo does not sufficiently reach and a distance from an object is far by using the distance between the object and an image pickup element, and correcting color temperature information at strobo flash. CONSTITUTION:In the case of strobo flash, a distance up to an object outputted by an AF sensor 10 and an arrival distance of a strobe are compared by a comparator circuit 11. Then color temperature information around the object at strobo non-flash and the color temperature information in response to the color temperature of the strobo are used and the result is calculated by a strobo color temperature information correction circuit 12 to obtain color temperature information for white balance control at strobo flash. Thus, even when the distance up to the object is far and the light of the strobo does not sufficiently reach the object, the white balance is made accurate regardless of the distance.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an electronic still camera device, and particularly to white balance control.

Conventional technology Conventionally, the white balance function of an electronic still camera device uses two types of color temperature information: one that corresponds to the color temperature of the surroundings of the subject, and the other that corresponds to the color temperature of the strobe light.
A method is used in which the color temperature is selected depending on the presence or absence of strobe light emission and white balance control is performed using the color temperature information.

An example of white balance control of a conventional electronic still camera device will be described below with reference to the drawings.

FIG. 3 shows a block diagram of a conventional electronic still camera device. In Figure 3, '/C, 1 is a WB that detects the red, blue, and green light components as color temperature information.
2 is a strobe color temperature information generator that generates fixed color information corresponding to the color temperature of the strobe light; 3 is a video signal processing circuit; 4 is a system control circuit; 6 is a storage device for storing still images of the subject. Image sensor, 6 is a 61 threshold circuit for strobe light emission, 7 is a strobe light, 8 is a switch that switches color temperature information depending on whether or not strobe light is emitted, and 9 is a recording circuit that records the image processed signal in 3. It is.

The white balance control operation of the conventional electronic still camera device configured as described above will be explained.

First, when adjusting the white balance, use the camera wg sensor 1 to select red, blue, and
Obtain color temperature information of green light component. Further, a strobe color temperature information generation circuit 11 obtains color temperature information corresponding to the color signal of the strobe light. The above two color temperature information are input to the changeover switch 8, and when the strobe light is emitted, the changeover switch 8 is inputted to the changeover switch 8.
is selected as the output side of the strobe color temperature emotion generating circuit 11, and when the strobe is not emitting light, the changeover switch 8 is selected as the output side of the mu WB sensor 1. Then, the signal accumulated in the ccn 5 during shooting is processed by the video signal processing circuit 3, and white balance control is performed according to the color temperature 1 signal outputted from the changeover switch 8, and the recording circuit 9 recorded in Aisfu by.

Problem to be Solved by the Invention However, in the above configuration, the color temperature information when the strobe is emitted is a fixed color output by the strobe color temperature information generator 11, regardless of the amount of strobe light irradiated to the subject. Since the white balance is controlled based on the temperature and clothing information, there was a problem that the white balance could not be controlled correctly when the subject was far away and the strobe light did not reach the subject sufficiently. .

In view of the above-mentioned problems, the present invention provides color temperature information of light components corresponding to each color component around the subject and a color temperature information generation circuit for the strobe when the distance to the subject is greater than the reachable distance of the strobe. By calculating the two color temperature information of the color temperature control signal for the color temperature of the output strobe light and controlling the white balance according to the distance to the subject, the white balance can be maintained regardless of the distance to the subject. The present invention provides an electronic still camera device that can be controlled correctly.

Means for Solving the Problems In order to solve the above-mentioned problems, the electronic photo camera device of the present invention includes an image sensor, a color temperature information detection means for detecting color temperature information around the object, and a sensor for detecting color temperature information around the object and the image sensor. A distance detection means for detecting a distance; a distance comparison means for comparing the distance detected by the distance detection means with a predetermined distance; and white balance control using the color temperature information detected by the color temperature information detection means. and a color temperature information generating means for generating color temperature information corresponding to the color temperature of the strobe, and when the strobe is emitted, the distance comparing means detects the subject detected by the distance detecting means at a predetermined distance. If it is determined that the distance is shorter, the white balance is controlled by the output of the color temperature information generating means that generates color temperature information according to the color temperature of the strobe, and the distance detecting means is used for a predetermined distance. If it is determined that the distance to the detected object is longer, the color temperature information 4 generates color temperature information corresponding to the color temperature information around the object detected by the color temperature information 4 detection means and the color temperature of the strobe. The present invention has a configuration in which white balance control is performed using color temperature information obtained by calculating two pieces of color temperature information of the temperature information generating means according to the distance detected by the distance detecting means. Depending on the configuration, even if the distance between the subject and the image sensor is far when the strobe is fired, and the strobe does not reach the subject sufficiently, the color temperature information is changed according to the distance, and the color temperature information is used to control the white balance. This allows for more accurate white balance control during strobe photography than before, regardless of the distance to the subject.

Embodiment μ Below, an electronic still camera device according to one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an electronic still camera device according to an embodiment of the present invention, and the same components as those in the configuration shown in FIG. 3 are given the same numbers and their explanations will be omitted.

10 in Fig. 1 is a 5F sensor that detects the distance between the subject and the image sensor, and 11 is the 905F sensor when the strobe is fired.
A comparison circuit 12 compares the sensor output and the strobe reach distance, and 12 is a strobe color temperature information correction circuit that generates color temperature information around the subject when the strobe is fired according to the output of the comparison circuit 11 when the strobe is fired. be.

FIG. 2 is a diagram showing a custom-made strobe color temperature information correction circuit of FIG. 11; The horizontal axis represents the distance l to the subject, and the vertical axis represents color temperature information for white balance control.

In this example, when the strobe fires, M) When 4≦L, color temperature information corresponding to the strobe color temperature B) When L < l, the color temperature information of the surroundings of the subject and the strobe color temperature when the strobe is not emitted. The two pieces of color temperature information are calculated in accordance with the distance β to the subject in such a way that the longer l becomes, the larger the ratio of the color temperature information around the subject becomes.

C) When L<l Color temperature information around the subject Use the blue white balance control.

In addition, in this implementation row, the strobe reach distance is L=c, 7
11L/y7Ia(1). Here, C=I'a is the guide number of the strobe, and FA is the aperture.

White balance control of the electronic still camera device configured as described above will be described. In the case of strobe light photography, the comparison circuit 11 compares the distance l to the subject outputted by the camera/sensor 10 with the strobe reach distance, and based on the comparison circuit 11, Using the color temperature information around the subject and the color temperature information corresponding to the color temperature of the strobe obtained in step B, the strobe color temperature information correction circuit 12 calculates the temperature to match the characteristics shown in FIG.
Obtain color temperature information for white balance control when flashing. The two color temperature information for the time of strobe light emission and the time of non-light emission are input to the changeover switch 8 and are selected by the control signal output from the system control circuit 4 according to the presence or absence of strobe light emission. The signals accumulated in the cans during shooting are processed by the video signal processing circuit 3, and
White balance control is performed using the color temperature information output from the changeover switch 8, and the information is recorded on the disc by the recording circuit 9.

As described above, according to this embodiment, the color temperature information when the strobe is emitted is corrected using the distance between the subject and the imaging probe, so if the subject is far away, the strobe light may not reach sufficiently. Accurate white balance control can be performed even when

Effects of the Invention As described above, according to the present invention, color temperature information during strobe light emission is corrected using the distance between the subject and the electronic still camera device, and white balance is controlled using the corrected color temperature information. Even when the distance to the subject becomes long and the strobe light does not reach the subject sufficiently, excellent effects can be obtained by accurately setting the white balance regardless of the distance.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an electronic still camera device of the present invention;
FIG. 2 is a characteristic diagram of a strobe color temperature information correction circuit of the electronic still camera device of the present invention, and FIG. 3 is a block diagram of a conventional electronic still camera device. DESCRIPTION OF SYMBOLS 1... WB sensor 12... Strobe color temperature information generator, 3... Video signal processing circuit, 4... System control circuit, 6...・・・・・・
caD, 6...control circuit, 7...strobe, 8...changeover switch, 9...
・Recording circuit, 1o...MuF sensor, 11...
. . . Comparison circuit, 12 . . . Color temperature information correction circuit for strobe.

Claims (1)

[Claims] an image sensor, a color temperature information detection means for detecting color temperature information around a subject, a distance detection means for detecting a distance between the subject and the image sensor, and a comparison between the distance detected by the distance detection means and a predetermined distance. a distance comparison means for performing white balance control based on the color temperature information detected by the color temperature information detection means, and a color temperature information generation means for generating color temperature information according to the color temperature of the strobe. When the strobe light is emitted, if the distance comparing means determines that the distance to the subject detected by the distance detecting means is shorter than the predetermined distance, color temperature information corresponding to the color temperature of the strobe is generated. The white balance is controlled by the output of the color temperature information generating means, and if it is determined that the distance to the subject detected by the distance detecting means is longer than the predetermined distance, the color temperature information detecting means detects the white balance. The two color temperature information of the color temperature information generation means that generates the color temperature information of the surroundings of the subject and the color temperature information corresponding to the color temperature of the strobe are processed according to the distance detected by the distance detection means. An electronic still camera device characterized by controlling white balance based on color temperature information.